Changes of Intracranial Pressure and Cerebral Blood Flow in Patients with Normal Pressure Hydrocephalus after Subarachnoid Hemorrhage

Object Cerebral ischemia remains the key cause of disability and death in the late phase after subarachnoid hemorrhage (SAH), and its pathogenesis is still poorly understood. The purpose of this study was to examine whether the change in intracranial pressure or the extravasated blood causes the late cerebral ischemia and the upregulation of receptors or the cerebral vasoconstriction observed following SAH. Methods Rats were allocated to 1 of 3 experimental conditions: 1) cisternal injection of 250 μl blood (SAH Group), 2) cisternal injection of 250 μl NaCl (Saline Group), or 3) the same procedure but without fluid injection (Sham Group). Two days after the procedure, the basilar and middle cerebral arteries were harvested, and contractile responses to endothelin (ET)–1 and 5-carboxamidotryptamine (5-CT) were investigated by means of myography. In addition, real-time polymerase chain reaction was used to determine the mRNA levels for ETA, ETB, and 5-HT1 receptors. Regional and global cerebral blood flow (CBF) were quantified by means of an autoradiographic technique. Results Compared with the sham condition, both SAH and saline injection resulted in significantly enhanced contraction of cerebral arteries in response to ET-1 and 5-CT. Regional and global CBF were reduced both in the Saline and SAH groups compared with the Sham Group. The mRNA levels for ETB and 5-HT1B receptors were upregulated after SAH and saline injection compared with the sham procedure. The effects in all parameters were more pronounced for SAH than for saline injection. Conclusions This study revealed that both the elevation of intracranial pressure and subarachnoid blood per se contribute approximately equally to the late CBF reductions and receptor upregulation following SAH.

Download Full-text

Pre-and postoperative cerebral blood flow changes in patients with idiopathic normal pressure hydrocephalus measured by computed tomography (CT)-perfusion

Journal of Cerebral Blood Flow & Metabolism ◽

10.1177/0271678x15608521 ◽

2016 ◽

Vol 36 (10) ◽

pp. 1755-1766 ◽

Cited By ~ 18

Author(s):

Doerthe Ziegelitz ◽

Jonathan Arvidsson ◽

Per Hellström ◽

Mats Tullberg ◽

Carsten Wikkelsø ◽

...

Keyword(s):

Computed Tomography ◽

Blood Flow ◽

Cerebral Blood Flow ◽

Normal Pressure Hydrocephalus ◽

Normal Pressure ◽

Idiopathic Normal Pressure Hydrocephalus ◽

Lentiform Nucleus ◽

Spatial Coverage ◽

Potential Biomarker ◽

Subcortical Regions

In idiopathic normal pressure hydrocephalus (iNPH), the cerebral blood flow (CBF) is of pathophysiological interest and a potential biomarker. Computed tomography perfusion (CTP), an established technique with high spatial resolution and quantitative measurements, has not yet been used in the iNPH context. If CTP were sensitive to the CBF levels and changes in iNPH, this technique might provide diagnostic and prognostic absolute perfusion thresholds. The aim of this work was to determine the applicability of CTP to iNPH. CBF measurements of 18 patients pre- and 17 three months postoperatively, and six healthy individuals (HI) were evaluated in 12 cortical and subcortical regions of interest. Correlations between CBF and symptomatology were analyzed in shunt-responders. Compared to HI, the preoperative CBF in iNPH was significantly reduced in normal appearing and periventricular white matter (PVWM), the lentiform nucleus and the global parenchyma. No CBF differences were shown between responders and non-responders. In responders, the CBF recovered postoperatively by 2.5–32% to approximately the level of HI, but remained significantly decreased in the PVWM of non-responders. The pre- and postoperative CBF of cortical and subcortical regions correlated with the intensity of symptoms. In spite of limited spatial coverage, CTP can measure CBF changes in iNPH.

Download Full-text

Cerebral blood flow in normal pressure hydrocephalus.

Stroke ◽

10.1161/01.str.18.6.1074 ◽

1987 ◽

Vol 18 (6) ◽

pp. 1074-1080 ◽

Cited By ~ 76

Author(s):

H L Mamo ◽

P C Meric ◽

J C Ponsin ◽

A C Rey ◽

A G Luft ◽

...

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Normal Pressure Hydrocephalus ◽

Normal Pressure

Download Full-text

Cerebral Blood Flow and Autoregulation in Normal Pressure Hydrocephalus

Neurosurgery ◽

10.1097/00006123-199706000-00009 ◽

1997 ◽

Vol 40 (6) ◽

pp. 1161-1167 ◽

Cited By ~ 81

Author(s):

Akira Tanaka ◽

Masato Kimura ◽

Yoshiya Nakayama ◽

Shinya Yoshinaga ◽

Masamichi Tomonaga

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Normal Pressure Hydrocephalus ◽

Normal Pressure

Download Full-text

Changes in Cerebral Blood Flow during Cerebrospinal Fluid Pressure Manipulation in Patients with Normal Pressure Hydrocephalus: A Methodological Study

Journal of Cerebral Blood Flow & Metabolism ◽

10.1097/00004647-200405000-00012 ◽

2004 ◽

Vol 24 (5) ◽

pp. 579-587 ◽

Cited By ~ 47

Author(s):

Brian K. Owler ◽

Alonso Pena ◽

Shahan Momjian ◽

Zofia Czosnyka ◽

Marek Czosnyka ◽

...

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Normal Pressure Hydrocephalus ◽

Fluid Pressure ◽

Three Dimensional ◽

Normal Pressure ◽

Element Analysis ◽

Csf Pressure ◽

Arterial Blood ◽

Positron Emission

The combination of cerebral blood flow measurement using 15O-water positron emission tomography with magnetic resonance coregistration and CSF infusion studies was used to study the global and regional changes in CBF with changes in CSF pressure in 15 patients with normal pressure hydrocephalus. With increases in CSF pressure, there was a variable increase in arterial blood pressure between individuals and global CBF was reduced, including in the cerebellum. Regionally, mean CBF decreased in the thalamus and basal ganglia, as well as in white matter regions. These reductions in CBF were significantly correlated with changes in the CSF pressure and with proximity to the ventricles. A three-dimensional finite-element analysis was used to analyze the effects on ventricular size and the distribution of stress during infusion. To study regional cerebral autoregulation in patients with possible normal pressure hydrocephalus, a sensitive CBF technique is required that provides absolute, not relative normalized, values for regional CBF and an adequate change in cerebral perfusion pressure must be provoked.

Download Full-text